1. Technical Field
The present disclosure relates generally to a surgical fastening device for applying surgical fasteners to body tissue. More particularly, the present disclosure relates to a surgical fastening device suitable for performing circular anastomosis and/or treatment to internal walls of hollow tissue organs.
2. Background of Related Art
Anastomosis is the surgical joining of separate hollow organ sections. Typically, an anastomosis procedure follows surgery in which a diseased or defective section of hollow tissue is removed and the remaining end sections are to be joined. Depending on the desired anastomosis procedure, the end sections may be joined by either circular, end-to-end or side-to-side organ reconstruction methods.
In a circular anastomosis procedure, the two ends of the organ sections are joined by means of a fastener instrument which drives a circular array of fasteners, e.g., staples, through the end section of each organ section and simultaneously cores any tissue interior of the driven circular array of staples to free the tubular passage. Examples of instruments for performing circular anastomosis of hollow organs are described in U.S. Pat. Nos. 6,053,390; 5,588,579; 5,119,983; 5,005,749; 4,646,745; 4,576,167; and 4,473,077, each of which is incorporated herein in its entirety by reference. Typically, these instruments include an elongated shaft having a handle portion at a proximal end to actuate the instrument and a fastener holding component disposed at a distal end. An anvil assembly including an anvil rod with attached anvil head is mounted to the distal end of the instrument adjacent the fastener holding component. Opposed end portions of tissue of the hollow organ(s) to be fastened are clamped between the anvil head and the fastener holding component. The clamped tissue is joined by driving one or more fasteners from the fastener holding component so that the ends of the fasteners pass through the tissue and are deformed by the anvil head. An annular knife is concurrently advanced to core tissue of the hollow organ to free a tubular passage within the organ.
In many surgical fastening devices for anastomosis procedures, the anvil assembly is configured such that the anvil head tilts or pivots relative to the anvil rod after a firing of the surgical fastening device to facilitate, e.g., removal or advancement of the surgical fastening device through tissue by presenting a smaller cross-sectional profile. However, given the close tolerances of the movable components of such a surgical fastening device, various movable components may interfere with the pivoting or tilting of the anvil head with respect to the anvil rod. Further, tissue surrounding the point of connection of the anvil head and anvil rod may interfere with the pivoting or tilting of the anvil head with respect to the anvil rod.
Accordingly, it would be desirable to provide a surgical fastening apparatus that is configured to secure components of the surgical fastening apparatus such that an anvil head may pivot freely with respect to an anvil rod. It would further be desirable to provide a surgical fastening apparatus configured to maintain tissue spaced away from the point of connection of an anvil rod and anvil head such that the anvil head may tilt or pivot freely with respect to the anvil rod.